JP2008217078A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep the security of a vehicle from decreasing by preventing a security system from malfunctioning. <P>SOLUTION: In a vehicle 10, an ECU 100 executes a security system control process to control the operating state of the security system 500. In this case, the ECU 100 executes an obstacle detection process to detect obstacle candidates from objects detected by a forward-looking millimeter-wave radar 300. In the obstacle detection process, for each of the objects detected, reflected wave strength Pr is compared with a threshold value S1 and obstacles with the strengths equal to or greater than S1 are regarded as obstacle candidates. Next, a determination is made as to whether or not a structure that is likely to cause errors in obstacle detection exists on the route of the vehicle 10; if such a structure exists, for the objects determined to be obstacle candidates beforehand, their reflected wave strength Pr is compared with a threshold value S2 greater than S1, and only the objects with the reflected wave strengths greater than the threshold value S2 are formally regarded as obstacle candidates. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technical field of a vehicle control device that controls a vehicle including a safety system for avoiding a collision with an obstacle, for example.

  As a conventional technique related to this type of apparatus, a technique for improving the detection accuracy of an obstacle has been proposed (see, for example, Patent Document 1). According to the vehicle obstacle recognition device disclosed in Patent Document 1 (hereinafter referred to as “conventional technology”), an object that has existed at least once within a predetermined time in a region that cannot be taken by a normal vehicle is not preceded. By determining that the vehicle is a vehicle, for example, when the vehicle is traveling on the end of an uphill, it is possible to prevent a signboard or a sign above that should originally meet the exclusion condition from being erroneously recognized as a preceding vehicle. It is said that.

  A technique for detecting an obstacle or a step based on a distance image output by a distance image sensor and outputting the position has also been proposed (for example, see Patent Document 2).

JP-A-11-38142 JP 2006-260105 A

  In a vehicle, for example, when detection of an object in front is performed using radio waves such as millimeter waves, for example, it generally relates to an angle in the vertical direction due to lower resolution than when using an image, for example. A structure is adopted in which information is not acquired. Alternatively, the resolution is not sufficient when the information about the angle in the vertical direction is acquired. However, in such object detection using radio waves, the radio waves have a specific beam width in the vertical direction, so as the distance from the vehicle increases, objects that are present in the vertical direction are noticeably detected. easy. In many cases, such an object is simply a structure on the road, which is different from the obstacle to be detected, and as a result, the detection accuracy of the obstacle tends to be lowered. However, when a configuration for recognizing an obstacle three-dimensionally as in the conventional technique is provided, the cost, installation space and processing load may be significantly increased, and the system may be enlarged.

  On the other hand, the detection results of such obstacles are closely related to the operating states of various safety systems mounted on the vehicle in order to improve the safety of the vehicle. This is likely to cause a malfunction of the safety system. Such a malfunction may rather impair the safety of the vehicle. That is, the conventional technique has a technical problem that it is difficult to effectively and effectively prevent a decrease in vehicle safety.

  This invention is made | formed in view of the problem mentioned above, and makes it a subject to provide the control apparatus of the vehicle which can suppress the fall of the safety | security of a vehicle efficiently and effectively.

  In order to solve the above-described problem, a vehicle control apparatus according to the present invention emits a detection wave having a predetermined wavelength in a forward detection range and reflects the reflected wave reflected on an object. And a vehicle control apparatus for controlling a vehicle having a safety system capable of improving safety during operation, wherein the detection is performed according to a predetermined criterion. First safety means for determining whether or not the detected object is an obstacle, and operating the safety system according to a predetermined operating standard for the object that has been determined to be the obstacle An operation control means; a second determination means for determining whether or not there is a structure that has been set in advance to cause an erroneous determination of the obstacle; and the fact that the structure exists. Judgment is line If it, said safety system is characterized by comprising a changing means for changing at least one of the determination reference and the reference operation so difficult to operate.

  The vehicle according to the present invention is provided with detection means that can take various modes such as various radio wave radars such as millimeter wave radars, laser radars or sonars, and can detect objects in a predetermined detection range set in front of the vehicle. Presence is detected as a reflected wave formed by reflecting a detection wave such as a millimeter wave emitted from these detection means on the object. Note that radio waves are employed as a preferred form of detection waves. Strictly speaking, the radio wave described here is a concept encompassing electromagnetic waves having a frequency of 30 Hz to 3 THz. However, as a preferred aspect, a millimeter wave of 30 to 300 GHz (for example, the 76 to 77 GHz band is used remarkably). Or infrared rays etc. are employ | adopted.

  The vehicle according to the present invention further includes various DSS (Driving Support System), for example, various safety systems such as PCS (Pre Crush Safety system), more specifically, For example, PB (Pre-crush Brake: Pre-crash Brake Control), PSB (Pre-crush Brake Assist: Pre-Crash Brake Assist), PBA (Pre-crush Brake Assist) Suspension control, output control of various alarm devices, various steering support control using EPS (Electronic Power Steering), for example, headrest control for head protection, seat control for human body protection , Various physical, mechanical, mechanical or electrical systems to realize various controls such as active hoods or active bumpers Or, further equipped with a driving load reduction system such as ACC (Adaptive Cruise Control), LKA (Lane Keeping Assist), or IPA (Intelligent Parking Assist) During operation, the safety of the vehicle is improved. In addition, “safety” described here includes, for example, collision safety as safety at the time of collision with an obstacle, and means that, for example, collision with an obstacle is avoided as a preferable aspect. This is intended to include preventive safety.

  According to the vehicle control apparatus of the present invention, for example, the first determination means that can take the form of various processing units such as an ECU (Electronic Control Unit), various controllers, various computer systems such as a microcomputer device, or the like. It is assumed that an obstacle can be detected at the time of its operation, for example, with sufficient reliability that at least a practically significant benefit can be enjoyed based on, for example, experimentally, empirically, theoretically or simulation. It is determined whether or not the detected object is an obstacle according to a predetermined determination criterion that is set and can adopt various modes according to the mode of the detection means.

  Here, the “obstacle” in the present invention is an object related to whether or not the various safety systems described above are activated, and the concept is included as a part of the object detected by the detection means. For example, an obstacle is a vehicle that exists in a detection range set in front of the vehicle, for example, whether it is stopped or traveling (hereinafter referred to as “front vehicle” as appropriate), or traveling of the vehicle. This refers to obstacles such as fallen objects, placed objects, or installed objects on the route. The obstacle typically refers to an object on the traveling route of the host vehicle that should be avoided by the host vehicle. However, as a preferred aspect, the driver does not perform the avoidance operation. This refers to the object to be avoided in situations where it can be determined that the driver cannot perform the avoidance operation, situations where the driver's avoidance operation is not in time, or situations where the driver is not aware of the object to be avoided, etc. . In other words, when the driver is in a physical or mental situation where an avoidance operation can be performed, and when there is sufficient time and space to allow the driver to perform an avoidance operation, the driver's avoidance operation can be determined to be in time In other words, it can be said that these objects to be avoided are objects that can become obstacles, that is, “obstacle candidates”. Therefore, the obstacle candidate and the obstacle are concepts that can point to the same object from the viewpoint of the physical properties of the object. Obstacles according to the present invention naturally include such obstacles and obstacle candidates.

  On the other hand, according to the vehicle control apparatus of the present invention, the operation control means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, during the operation, Operate the safety system for objects that have been identified as obstacles by means (ie, objects detected as obstacles), for example, to avoid collision or contact with the obstacles in accordance with predetermined operating criteria Let

  Here, the “operation standard” according to the present invention may cause a collision with the vehicle or avoid a collision with the vehicle, for example, in the front region of the vehicle, more specifically, for example, on the travel route of the vehicle. In order to activate the above-described safety system without a collision avoiding operation such as a braking operation or a steering operation by a driver when it is difficult or the presence of an obstacle as an object for which the vehicle should avoid a collision is detected. A concept that encompasses control conditions, for example, the distance between a vehicle and an obstacle that should activate the safety system (ie, define the timing of operation), the time to collision or contact with the obstacle, or safety It is intended to include the scale of operation such as how much the system is operated.

  By controlling the safety system according to these operating standards, for example, when the relative distance between the obstacle and the vehicle becomes a predetermined value or less, or when the vehicle travels at the current vehicle speed, it collides with the obstacle. For example, when the time until the time is less than a predetermined value, for example, braking force is applied to the wheels, or the pressure on the seat belt is increased, or a warning is given to the driver. Can be avoided, or the impact at the time of the collision can be buffered, or the behavior change of the vehicle before and after the collision can be suppressed, and safer driving in the vehicle can be ensured. That is, safety can be improved.

  Here, in particular, the detection means has a configuration for detecting the object as a reflected wave formed by reflecting the detection wave on the object. However, such a detection wave, particularly a radio wave such as a millimeter wave, is so far away from the vehicle. Since the beam width tends to expand easily in the vertical direction of the vehicle, or moreover, the reflected wave often does not accompany the information in the vertical direction, so except for a relatively short range from the vehicle, for example, To the extent that an object that is difficult to classify as an obstacle, such as an overbridge, a footbridge, a three-dimensional intersection road, a road surface step, a bridge, a guardrail, an installation sign, a bulletin board, or a tonnell, is misclassified as an obstacle, that is, the discrimination criteria described above. May be detected as a reflected wave that can satisfy the above. That is, there is a possibility that an erroneous detection of an obstacle occurs as an obstacle is detected in error. Such an erroneous detection of an obstacle leads to a malfunction of the various safety systems described above, and may reduce the safety of the vehicle.

  Therefore, the vehicle control apparatus according to the present invention suppresses a decrease in safety due to such an erroneous detection of an obstacle as follows. That is, according to the vehicle control apparatus of the present invention, the second determination means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, for example, in front of the vehicle, for example, the vehicle Whether or not there is a preset structure above or below the vehicle travel route or around the vehicle (including whether the vehicle is in a travel state that can be considered to exist) ) Is determined. Further, when it is determined that such a structure exists, the safety system is changed by a changing means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. At least one of the discrimination criterion and the operation criterion described above is changed so that the operation becomes difficult.

  Here, the “structure” according to the present invention is set in advance as a thing that causes an erroneous determination of an obstacle (including a case where there is a considerable possibility of inviting the obstacle), for example, as described above , Overbridge, pedestrian bridge, overpass, road level difference, bridge, guardrail, installation sign, bulletin board or tunnel. The discriminating mode according to the second discriminating means is as long as it can accurately discriminate whether or not such a structure exists in front of the vehicle, at least to the extent that it can provide some significant profit in practice. This is not a limitation, and when a vehicle has a car navigation device or a device equivalent thereto, necessary information (for example, position information of the vehicle and various structures including the structure) is acquired from these devices. , It may be used for the determination. Or, for example, when a driver inputs a physical, mechanical, or electrical input by operating some operation means provided in the vehicle, for example, it is determined that the structure exists. Also good. Alternatively, when a device that outputs a wireless signal or the like that informs the existence of the structure as infrastructure equipment is installed in advance, the determination is made by receiving this type of signal. Also good.

  On the other hand, the changing means changes the discriminant criteria for determining whether or not the detected object is an obstacle and / or the operating criteria of the safety system so that the various safety systems described above are difficult to operate. To do. That is, the changing means is, for example, (i) a basic determination criterion that is set in advance so that the determination that the object detected by the detection means is an obstacle is relatively difficult to occur, preferably Perform some numerical operation or logical operation processing on some threshold, or perform numerical operation independent of the basic discrimination criterion according to an appropriate algorithm set in advance, or correspond from an appropriate map, etc. The decision criterion may be changed as a concept that includes setting the discrimination criterion separately from the basic discrimination criterion by selecting a value to be determined, or (ii) The operating standard may be changed so that the safety system operates after approaching an obstacle more or less so that the safety system operates lightly or slowly. The control of both these, for example in each case is determined based on the running condition of the vehicle, or may be performed in cooperation with each other according to a pre-adapted weighting.

  Thus, according to the vehicle control device of the present invention, when the structure described above is present in front of the vehicle, or when it is considered that the structure is present, the operation standard of the safety system is changed. It is possible to make it difficult to operate the safety system by changing the determination criterion located upstream in the control with respect to such an operation criterion, or by performing both. Therefore, the safety system reduces the possibility of malfunctioning due to an erroneous detection of an obstacle, detects an object while ensuring a significant resolution in the vertical direction, and significantly increases costs, installation space and processing load, and the system. Therefore, it is possible to suppress a decrease in the safety of the vehicle without having a configuration that can lead to an enlargement of the vehicle.

  Note that, depending on how the discrimination criterion and the operation criterion are changed, it is possible to make the safety system easy to operate or to make it difficult to operate as described above. Therefore, the changing means is set, for example, in a state where the safety system is relatively easy to operate in the basic state (or a state that can be regarded as such), and based on the determination result related to the second determination means (that is, the structure At least one of the safety systems may be changed so that the safety system is set to be relatively difficult to operate (for example, the safety vision system is relatively difficult to operate in the basic state). And at least one of them is changed so that the safety system is set to be relatively easy to operate based on the determination result of the second determination means (that is, when there is no structure). Also good.

  In one aspect of the vehicle control apparatus according to the present invention, the structure includes a vertical structure that exists in the vertical direction of the vehicle and a step that exists on a travel route of the vehicle.

  Obstacles may be detected erroneously when the detection means mainly detects such upper and lower structures and steps on the travel route as objects. Therefore, the vehicle control device according to the present invention is remarkably effective when such a structure includes such a vertical structure or a step.

  In another aspect of the vehicle control apparatus according to the present invention, the vehicle further includes position information acquisition means capable of acquiring a predetermined type of position information regarding the position of the vehicle and the position of the structure, The second determining means determines whether or not the structure exists based on the acquired position information.

  According to this aspect, the vehicle is provided with position information acquisition means that can take an aspect such as a positioning system using a car navigation device or GPS (Global Positioning System), for example. This type of position information is a predetermined type of position information as a concept that includes information that can specify the traveling position of the vehicle and the traveling position of the structure, such as the appropriate coordinate position on the map or absolute position including latitude, longitude, altitude, etc. By acquiring from the information acquisition means, it is possible to determine with high accuracy whether there is a structure in front of the vehicle. The safety system according to the present invention is basically provided for the purpose of safety of the vehicle, and the limitation of the operation (in other words, the reduction of the operation sensitivity) caused by the change of the discrimination standard and the operation standard is a malfunction. It should be avoided as much as possible while preventing it. Therefore, when it is possible to determine with high accuracy whether or not a structure exists in this way, the safety of the vehicle can be assured as much as possible.

  When such a car navigation device or the like is mounted on a vehicle, it is possible to estimate a near-future travel route if a travel route is set in advance or in view of a travel history, surrounding road environment, and the like. In some cases, it is possible to store in advance the state of the near future structure. In such a case, it is possible to smoothly execute the determination process related to the second determination unit based on the stored information on the presence state, which is preferable.

  In another aspect of the vehicle control apparatus according to the present invention, the first determination means is detected based on a comparison between an index value corresponding to the intensity of the received reflected wave and a first threshold value. It is determined whether or not the object is an obstacle, and the changing means changes the threshold value as at least the determination criterion.

  According to this aspect, the index value as a concept including the intensity of the reflected wave, or some index value that may have a one-to-one, one-to-many, many-to-one or many-to-many relationship with the intensity of the reflected wave, for example, It is set in advance so that it can be determined that the detected object is an obstacle at least to the extent that it does not reveal a practical problem based on experiment, experience, theory or simulation. Based on the comparison with the threshold value of 1, it is determined whether or not the detected object is an obstacle. At this time, the changing means performs, for example, some numerical operation or logical operation processing on the reference value, or numerical operation or logical operation on a value different from the basic value according to an appropriate algorithm set in advance, for example. By changing the first threshold value by performing an operation or selecting a corresponding value from an appropriate map or the like, for example, at least the above-described discrimination criterion is changed and the operation of the safety system is limited.

  Therefore, according to this aspect, the obstacle can be detected quickly and accurately according to the comparison determination between the index value and the first threshold value, and the decrease in the safety can be quickly and effectively performed by changing the first threshold value. It becomes possible to suppress.

  In another aspect of the vehicle control apparatus according to the present invention, the vehicle control device further includes an acquisition unit configured to acquire a collision prediction time that represents a time required for the object that has been determined to be the obstacle to collide with the vehicle. The operation control means activates the safety system based on a comparison between the acquired predicted collision time and a second threshold value, and the change means changes the second threshold value as at least the operation reference. To do.

  According to this aspect, for example, the acquisition unit that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, the vehicle and the object to be analyzed based on the acquired reflected wave, for example, For example, the predicted collision time is obtained based on information on the distance of the vehicle and information on the vehicle speed obtained through detection means such as a vehicle speed sensor. Based on the comparison between the acquired predicted collision time and the second threshold value, the operation control unit may, as a preferred aspect, acquire the predicted collision time less than (or less than) the second threshold value. The safety system is activated in the event of a failure.

  Here, the changing means changes the second threshold value at least as the operation standard described above. For this reason, it becomes possible to change the operation timing of a safety system simply, and the fall of safety is controlled suitably.

  Further, the second threshold value is set for each of the devices constituting the safety system, for example, experimentally, empirically, theoretically, or based on simulations. More specifically, for example, the operation opportunity may be selected so that the vehicle can be operated at an appropriate timing according to the purpose of changing the behavior of the vehicle, protecting the driver, giving a warning to the driver, or the like. It may be determined individually and concretely so as not to give the driver dissatisfaction with drivability and comfort by increasing more than necessary, and so that the operation of the safety system is not delayed. In this case, for example, it is possible to cope with the change only to the second threshold value that really needs to be changed. For example, “Although the warning may be performed regardless of the presence or absence of the structure, the braking device This is useful in practice because it enables finer control, such as delaying the operation timing of the system when there is a structure.

  In another aspect of the vehicle control apparatus according to the present invention, the vehicle control device further includes third determining means for determining whether or not the detected object is a stationary object, and the changing means is the stationary object. The at least one corresponding to the object for which the determination is made is changed.

  According to this aspect, for example, the relative speed between the vehicle and the detected object can be adjusted by the third discriminating means that can take the form of various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device. Based on this, the object detected by the detection means is a stationary object as a concept including various patterns such as road surfaces, pedestrian crossings or road signs, or various structures such as overbridges, guardrails, installation signs, bulletin boards or tunnels ( In other words, it is determined whether or not the relative speed with respect to the road surface is zero or an object that can be regarded as zero.

  Here, the changing means limits the operation of the safety system by changing at least one of the determination criterion and the operation criterion corresponding to the object that has been determined to be a stationary object. In other words, according to this aspect, an object that is determined to be a stationary object or an obstacle that is determined to be a stationary object (that is, an object that has been determined to be an obstacle). On the other hand, at least preferentially (preferably only for such objects), the operation of the safety system is limited.

  An object that is not a stationary object (that is, an object having a non-zero value relative to the road surface, which can be judged as a forward vehicle (including an oncoming vehicle) with high probability at least in practice) is an object that can be an obstacle. In other words, it is an object that is unlikely to be erroneously detected as being detected as an obstacle, and is remarkably not such an object. Therefore, the determination criterion or the operation criterion relating to the stationary object is at least preferentially changed, so that the above-described erroneous determination that the structure is an obstacle is performed (that is, the obstacle is erroneously detected). In practice, extremely high benefits are enjoyed, such as ensuring the opportunity of operation of the safety system as much as possible while reducing the possibility (or frequency or degree).

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

<Embodiment of the Invention>
Hereinafter, various preferred embodiments of the present invention will be described with reference to the drawings as appropriate.

<First Embodiment>
<Configuration of Embodiment>
First, the configuration of the vehicle 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram conceptually showing a configuration of a portion of the vehicle 10 related to the vehicle control device according to the present invention.

  In FIG. 1, a vehicle 10 includes an ECU 100, a navigation device 200, a forward millimeter wave radar 300, a vehicle speed sensor 400, and a safety system 500.

  The ECU 100 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown) and can control the operation of each element of FIG. 1 including an engine (not shown). 1 is an example of a “vehicle control device” according to the present invention configured. The ECU 100 is configured to be able to execute a safety system control process, which will be described later, according to a control program stored in the ROM.

  The navigation device 200 is displayed on various display means such as a liquid crystal display panel installed on the front console panel of the vehicle 10 based on map data stored in an appropriate storage means such as an HDD (Hard Disk Drive). It is an example of a “position information acquisition unit” according to the present invention configured to be able to display information on an absolute position obtained via various positioning systems such as GPS on a map screen. The navigation device 200 is electrically connected to the ECU 100 and is data relating to the road on which the vehicle 10 is traveling, more specifically, data representing the current position of the vehicle 10, data relating to roads around the vehicle 10 ( For example, road type, road width, number of lanes, speed limit, road shape, etc.) and structures installed around the vehicle 10 (ie, “structures” according to the present invention are examples of A structure that can exist in a direction perpendicular to the vehicle 10 (that is, an example of the “vertical direction” according to the present invention) such as a bridge, a pedestrian bridge, a three-dimensional intersection road, a tunnel, or a bridge (that is, the “vertical direction structure according to the present invention”). An example), a step on the road surface (for example, an example of a “step” according to the present invention including a paved road under construction, a bridge entrance / exit and a corner step on the shoulder of the road), or the like. Structure data, etc. (including guardrails, installation signs, road information bulletin boards, etc.) is constant or constant as long as the positioning system is in operation, regardless of whether a map screen is displayed on the display means. The ECU 100 is configured to have an indefinite cycle.

  The front millimeter wave radar 300 can emit a millimeter wave for object detection (that is, an example of the “detection wave” according to the present invention) to the front area of the vehicle 10 and the outgoing wave reflected on the object in the front area. It is an example of the “detecting means” according to the present invention configured to be able to receive a reflected wave. The forward millimeter wave radar 300 is electrically connected to the ECU 100, and the operation state thereof is controlled by the ECU 100 to the upper level. The forward millimeter wave radar 300 further determines the position of the object (preferably the distance from the vehicle 10), the relative speed of the vehicle 10 with respect to the object, and the like based on the propagation time of the emitted millimeter wave and the frequency difference caused by the Doppler effect. Can be detected.

  The vehicle speed sensor 400 is a sensor configured to be able to detect the vehicle speed Vv that is the speed of the vehicle 10. The vehicle speed sensor 400 is electrically connected to the ECU 100, and the detected vehicle speed Vv is grasped by the ECU 100 constantly or at a constant or indefinite period.

  The safety system 500 is an example of a “safety system” according to the present invention configured to improve the safety of the vehicle 10, and includes a braking device 510, a seat belt control device 520, and an alarm device 530. Become. It should be noted that the elements constituting the safety system 500 may naturally include those used for normal traveling control in the vehicle 10 such as the braking device 510, for example.

  The braking device 510 is an example of a “braking unit” according to the present invention configured to be able to apply a braking force to a wheel (not shown) of the vehicle 10. The braking device 510 may apply a braking force according to the hydraulic pressure of the hydraulic fluid transmitted to a wheel cylinder or the like provided in each wheel via a transmission means such as a brake actuator in accordance with the operation of the brake pedal by the driver. This is a disc brake device configured to be possible. In addition, the aspect of the braking device 510 is not limited to this. Since the brake actuator described above is under the control of the ECU 100, a braking force can be automatically applied to each wheel independently of the braking operation by the driver (such as the depression of the brake pedal described above). It has a configuration.

  The seat belt control device 520 is a protection means for protecting the body of the passenger of the vehicle 10 including the driver. The seat belt control device 520 is configured to include a belt unit that physically protects an occupant, and a control system that controls the pressure applied to the belt, and the control system is controlled by the ECU 100 in a higher level. It has a configuration. Therefore, the pressure applied when the belt portion protects the occupant is controlled by the ECU 100.

  The alarm device 530 is an alarm device disposed on, for example, the front console panel of the vehicle 10. The alarm device 530 is electrically connected to the ECU 100, and when activated by the ECU 100, an alarm or warning sound of a predetermined volume flows in the vehicle interior.

<Operation of Embodiment>
<Details of safety system control processing>
The braking device 510, the seat belt control device 520, and the alarm device 530 constituting the safety system 500 cooperate with each other to improve the safety of the vehicle 10 by the ECU 100 when an obstacle exists in the front area of the vehicle 10. Be controlled. At this time, the operating state of each device is controlled by a safety system control process executed by the ECU 100.

  Here, details of the safety system control process will be described with reference to FIG. FIG. 2 is a flowchart of the safety system control process.

  In FIG. 2, the ECU 100 executes an obstacle detection process (step S100). Here, the details of the obstacle detection processing will be described with reference to FIG. FIG. 3 is a flowchart of the obstacle detection process.

  In FIG. 3, the ECU 100 detects the intensity of the millimeter wave (that is, the reflected wave) reflected from an object existing in the front area of the vehicle 10 from the front millimeter wave radar 300 (hereinafter referred to as “reflected wave intensity” as appropriate) Pr. Is acquired (step S101). The reflected wave intensity Pr is an example of “an index value corresponding to the intensity of the reflected wave” according to the present invention. When the reflected wave is acquired as the reflected wave intensity Pr, the presence of an object in the front area of the vehicle 10 is detected. Next, the ECU 100 determines that the detected object is an obstacle based on a comparison between the acquired reflected wave intensity Pr and a preset threshold value S (that is, an example of the “first threshold value” according to the present invention). It is determined whether or not it is an object (step S102). That is, the threshold value S is an example of the “discrimination criterion” according to the present invention.

  Here, the characteristic of the threshold value S will be described with reference to FIG. FIG. 4 is a schematic diagram conceptually showing the characteristic of the threshold value S.

  In FIG. 4, the threshold value S is represented as an indicated characteristic line PRF_S1 (refer to a chain line) in a coordinate system in which the vertical axis and the horizontal axis represent the reflected wave intensity Pr and the distance L to the object, respectively. As illustrated, the characteristic line PRF_S1 is expressed as a curve that decreases as the distance L increases, that is, as the distance from the vehicle 10 increases. In the processing according to step A102 in FIG. 3, the ECU 100 obtains the acquired reflected wave intensity Pr and the threshold S defined by PRF_S1 in the distance to the object corresponding to the reflected intensity Pr (here, for convenience, the threshold S1 and the threshold S1). And the object corresponding to the reflected wave intensity Pr is an object that can be an obstacle (that is, the above-described obstacle candidate). Determine that there is. In the following description, an object having a reflected wave intensity equal to or higher than the threshold value S is appropriately expressed as an “obstacle candidate”.

  Returning to FIG. 3, the ECU 100 determines whether there is an obstacle candidate as a result of the processing in step S102 (step S103). When there is no obstacle candidate (step S103: NO), the ECU 100 shifts the process to step S109, sets the obstacle flag that defines the presence or absence of the obstacle candidate to OFF, and ends the obstacle detection process. The obstacle flag is a flag that indicates that an obstacle candidate exists when it is “ON”, and that an obstacle candidate does not exist when it is “OFF”.

  In the process according to step S103, as described above, the number of peaks of the reflected wave intensity Pr that is equal to or higher than the threshold value S (here, the threshold value S1) is acquired as the obstacle candidate number N. At this time, for each of the obstacle candidates, the distance L representing the distance to the vehicle 10 and the relative speed Vr of the vehicle 10 with respect to each of the obstacle candidates are acquired together. The obtained number of obstacle candidates N and the peak value, distance L, and relative speed Vr corresponding to each obstacle candidate are temporarily stored in the RAM of the ECU 100. The obstacle candidate may not necessarily be detected as a peak of the reflected wave intensity Pr.

  When an obstacle candidate exists (step S103: YES), the ECU 100 determines whether or not a predetermined structure exists on the travel route of the vehicle 10 (step S104). Here, the “structure” according to the present embodiment is originally a candidate for the obstacle due to the insufficient resolution in the vertical direction and the diffusion of the outgoing wave generated according to the outgoing distance in the forward millimeter wave radar 300. A structure that may be erroneously detected as an obstacle candidate even though it is not obtained, such as an overbridge, a pedestrian bridge, a three-dimensional intersection road, a tunnel, or a bridge, , And road surface steps (including paved roads under construction, bridge doorways, and shoulder shoulder corner steps). Further, depending on the travel route and travel state of the vehicle 10, there are structures that cause erroneous detection of such obstacle candidates only in a specific travel route and travel state. Therefore, in the process according to step S104, a structure that has been set in advance as having such a property, or a structure that can be regarded as having such a property at least (that is, in other words, the vehicle 10 has such a property as described above). The presence or absence of a driving situation (including whether the vehicle is in a driving route, a driving condition, an environmental condition, or the like) that may cause a false detection of an obstacle candidate is determined. At this time, the ECU 100 performs the determination based on the above-described “data relating to the road on which the vehicle 10 is traveling” acquired from the navigation device 200 at a constant or indefinite period. As a result of the determination, when such a structure does not exist (or when the traveling state of the vehicle 10 does not generate such a structure) (step S104: NO), the ECU 100 determines whether the obstacle is a candidate. The obstacle flag is set to ON (step S108), and the obstacle detection process is terminated.

  On the other hand, when such a structure exists (step S104: YES), the ECU 100 changes the threshold value S of the reflected wave intensity Pr related to the above-described obstacle candidate detection from S1 to S2 (S2> S1) ( In step S105, the obstacle candidate is detected again (step S106).

  Here, the threshold value S after such a change will be described with reference to FIG. FIG. 5 is another schematic diagram conceptually showing the characteristic of the threshold value S. In the figure, the same reference numerals are given to the same portions as those in FIG. 4, and the description thereof will be omitted as appropriate.

  In FIG. 5, the threshold value S is represented as a characteristic line PRF_S2 (solid line) in a coordinate system in which the vertical axis and the horizontal axis represent the reflected wave intensity Pr and the distance L from the vehicle 10 in the front area. As shown in the figure, the characteristic line PRF_S2 is a curve that decreases as the distance L becomes longer, that is, away from the vehicle 10, and has the same waveform as the characteristic line PRF_S1 (one-dot chain line) described above, and the characteristic line PRF_S1. Is raised by giving a predetermined offset. The ECU 100 adds the predetermined value to the threshold value S before the change (that is, the threshold value S1) in the process according to step S105 in FIG. 3, thereby setting the threshold value S1 to the threshold value that is defined by the characteristic line PRF_S2 (that is, the threshold value). Change to S2). Note that the mode of changing the threshold value S is not limited to that described above, and the threshold value S1 decreases as the distance L increases with respect to the threshold value S1, for example, as represented by a characteristic line PRF_S2 ′ in FIG. The value may be changed to a value obtained by adding the addition amount. That is, in this case, as the distance L increases, the curves that define the threshold value S before and after the change gradually approach each other.

  Returning to FIG. 3, the ECU 100 determines whether or not an obstacle candidate is detected as a result of the determination processing in step S106 (step S107). At this time, information (a peak value or a relative value) regarding an object (that is, an object whose reflected wave intensity is S1 ≦ Pr <S2) newly determined to be not an obstacle candidate by a relatively large threshold S is determined. Information such as speed) is discarded. If there is no obstacle candidate as a result of the determination processing in step S107 (step S107: NO), the ECU 100 determines that all of the objects that are once regarded as obstacle candidates are structures on the travel route of the vehicle 10. Yes, because it is not a candidate for an obstacle, or there is a possibility of such a structure, and it is better not to consider it as a candidate for an obstacle from the viewpoint of preventing malfunction of the safety system 500. The object flag is set to OFF (step S109).

On the other hand, it is determined that the object having the reflected wave intensity larger than the threshold value S2 reset so as to be relatively large is not a structure as described above, and the ECU 100 determines the above-described information regarding these. Are stored in the RAM, the obstacle flag is set to ON, and the obstacle detection process is terminated. That is, through the obstacle detection process, the probability that the candidate is finally an obstacle candidate is relatively high (that is, the malfunction of the safety system 500 is at least not practically revealing a failure). 2), only the object is treated as an obstacle candidate with information such as the relative distance to the vehicle 10. Returning to FIG. 2, through such an obstacle detection process, the ECU 100 It is determined whether or not the flag is set to ON (step S10). When the obstacle flag is set to OFF (step S10: NO), the ECU 100 sets the collision flag to OFF, assuming that there is no obstacle candidate to be avoided (that is, an object that can be an obstacle) (step S10). S14). Here, the collision flag is a flag that defines the timing at which the safety system 500 should be activated. When the collision flag is set to ON, each device constituting the safety system 500 is activated. . If the obstacle flag is OFF, there is no obstacle candidate to be avoided, so the collision flag is inevitably set to OFF.

  On the other hand, when the obstacle flag is set to ON (step S10: YES), the ECU 100 sets the threshold value Ct of the collision prediction time TTC that represents the time until the collision between the vehicle 10 and the obstacle candidate occurs to Ct1. (Step S11). Here, whether or not each of the devices constituting the safety system 500 can be operated is defined by a collision flag that is individually set for each. When the collision flag is set to ON, the collision flag that is set to ON is set. Each device corresponding to is configured to operate. The threshold value Ct1 is different among the devices constituting the safety system 500. The braking device 510 is, for example, 0.6 seconds, the seat belt control device 520 is, for example, 0.8 seconds, and the alarm device 530 is, for example, 2 seconds. Seconds. That is, in this case, the braking device 510 applies a braking force to the wheel 0.6 seconds before the collision with the obstacle, and the seat belt control device 520 determines that the seat belt is operated 0.8 seconds before the collision with the obstacle. The landing pressure is increased, and the alarm device 530 gives a warning to the driver 2 seconds before the collision with the obstacle. The threshold value Ct for the predicted collision time is an example of the “operation standard” and the “second threshold value” according to the present invention.

  When the threshold Ct of the collision prediction time TTC is set to Ct1, the ECU 100 calculates the collision prediction time TTC according to the following equation (1) for the detected obstacle candidate, and the calculated collision prediction time TTC is the threshold Ct ( Here, it is determined whether or not it is less than Ct1) (step S12).

TTC = L / Vr (1)
Here, in Expression (1), L is the distance between the vehicle 10 and the obstacle candidate, and Vr is the relative speed of the vehicle 10 with respect to the obstacle candidate. As described above, these are stored in the RAM for each obstacle candidate detected in the execution process of the obstacle detection process described above. As is clear from the purpose of avoiding a collision with an obstacle, in this case, the relative speed Vr of the vehicle 10 with respect to the obstacle candidate is a positive value. Accompanying is a condition.

  If the collision prediction time TTC is equal to or greater than the threshold value Ct as a result of the determination processing in step S12 (step S12: NO), the ECU 100 determines that it is not the operation timing of each device constituting the safety system 500, and The flag is set to OFF (step S14). On the other hand, when the predicted collision time TTC is less than the threshold value Ct (step S12: YES), the ECU 100 sets the collision flag to ON (step S13). That is, in this case, one or a plurality of devices corresponding to the collision flag set to ON among the devices constituting the safety system 500 operate. Although illustration is omitted in FIG. 2 for the purpose of preventing the drawing from becoming complicated, the ECU 100 performs steps S11 and S1 corresponding to the number of obstacles detected in the obstacle detection process and the number of devices constituting the safety system 500. Step S12 is repeated. When the process according to step S13 or step S14 is executed, the ECU 100 returns the process to step S100 and again executes a series of processes starting from the obstacle detection process.

  As described above, according to the safety system control process according to the first embodiment, in the execution process of the obstacle detection process, the presence of a structure that may cause an erroneous detection of an obstacle candidate is taken into consideration. When such a structure exists in the travel route, or when the traveling state of the vehicle 10 can cause such a structure to exist, it is used to determine whether or not the detected object is an obstacle candidate. The threshold value to be applied is further expanded. Accordingly, it is difficult to determine that the detected object is an obstacle candidate, and as a result, the operation opportunity of the safety system 500 decreases. In other words, the safety system 500 becomes difficult to operate on the erroneously detected obstacle candidate, and the safety of the vehicle 10 is improved.

Second Embodiment
In the first embodiment described above, the threshold value S of the reflected wave Pr is changed as the “discrimination criterion” according to the present invention, but the mode of making the safety system 500 difficult to operate is not limited to this. Here, with reference to FIG. 6, the safety system control process according to the second embodiment of the present invention will be described. FIG. 6 is a flowchart of the safety system control process according to the second embodiment of the present invention. In the figure, the same reference numerals are assigned to the same portions as those in FIGS. 2 and 3, and the description thereof is omitted as appropriate.

  In FIG. 6, the ECU 100 acquires the reflected wave intensity Pr (step S101), sets the threshold value S to S1 described above, and detects an obstacle candidate (step S102). If no obstacle candidate is detected (step S103: NO), the ECU 100 returns the process to step S101, repeats a series of processes, and if an obstacle candidate is detected (step S103: YES), the collision flag. A setting process is executed (step S300). That is, in the safety system control process according to the second embodiment, the obstacle candidate detection itself is performed according to the threshold value S1 having a fixed characteristic. Therefore, at this time, depending on the traveling state of the vehicle 10, there is a possibility that an obstacle candidate is erroneously detected due to the influence of the structure described above. Therefore, the second embodiment is configured to eliminate the influence of the structure in the collision flag setting process. When the collision flag setting process is executed, the process returns to step S101, and a series of processes is repeated.

  Here, the details of the collision flag setting process will be described with reference to FIG. FIG. 7 is a flowchart of the collision flag setting process. In the figure, the same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

  In FIG. 7, the ECU 100 acquires the distance L to the vehicle 10 and the relative speed Vr for each obstacle candidate that has already been detected, and acquires the vehicle speed Vv of the vehicle 10 from the vehicle speed sensor 400 (step S301). . Note that the distance L and the relative velocity Vr are calculated based on the millimeter wave propagation time, the frequency difference caused by the Doppler effect, and the like when the object is detected by the forward millimeter wave radar 300 as described above. Next, the ECU 100 calculates the difference between the acquired relative speed Vr and the vehicle speed Vv, and determines whether or not the calculation result is less than the reference value C (step S302).

  Here, the reference value C is set to zero or a value that is small enough to be regarded as zero, and the process according to step S302 determines whether or not the detected obstacle candidate is a stationary object. It is processing. More specifically, if the obstacle candidate is a stationary object, the relative speed Vr with respect to the vehicle 10 is substantially the same as the vehicle speed Vv, the absolute value becomes relatively small, and the determination processing according to step S302 is performed. “YES”. On the other hand, if the obstacle candidate is a forward vehicle or the like, the relative speed Vr becomes a sufficiently small value with respect to the vehicle speed Vv, although there is a difference in the vehicle speed, and the absolute value becomes relatively large, and the determination related to step S302. The process is “NO”. If the obstacle candidate is not a stationary object (step S302: NO), the process proceeds to step S11. That is, as in the first embodiment, the threshold value Ct of the collision prediction time TTC is set to Ct1.

  If the obstacle candidate is a stationary object (step S302: YES), the ECU 100 determines whether a predetermined structure such as a tunnel or a road surface step exists on the traveling route of the vehicle 10, as described in the first embodiment. It is determined whether or not (step S104). When there is no structure (step S104: NO), the ECU 100 determines that the detected obstacle candidate can be an operation target of the safety system 500, shifts the processing to step S11, and threshold value Ct of the collision prediction time TTC. Is set to Ct1. On the other hand, when the structure exists (step S104: YES), the ECU 100 sets the threshold value Ct of the collision prediction time TTC to Ct2 that is smaller than Ct1 (step S303).

  When the threshold value Ct of the collision prediction time TTC is set by the processing according to step S11 or step S303, the ECU 100 calculates the collision prediction time TTC as described in the first embodiment, and executes comparison and determination with the threshold value Ct (step). In step S12, the collision flag is set to ON (step S13) or OFF (step S14) according to the determination result. When the setting of the collision flag ends, the collision flag setting process ends. Although omitted in FIG. 7, the series of processes related to step S301 to step S13 or step S14 related to the collision flag setting process is naturally performed for each detected obstacle candidate.

  Here, in particular, in the process according to step S12, unlike the first embodiment, the collision prediction time TTC in which the collision flag is set to ON changes depending on which of the processes of step S303 and step S11 is performed. That is, when the threshold value is set to Ct2 in the process according to step S303, the collision flag is set to ON when the collision prediction time TTC becomes a value smaller than Ct1. Therefore, qualitatively speaking, the safety system 500 is relatively difficult to operate. As described above, according to the present embodiment, even when the criterion for determining whether or not a detected object is an obstacle candidate is uniform, when a predetermined structure exists, the present invention is related to the present invention. The threshold value Ct of the predicted collision time TTC, which is an example of the “operation standard”, is corrected to a smaller side, that is, a side on which the safety system 500 is difficult to operate. Opportunities to operate are reduced. That is, a decrease in safety due to malfunction of the safety system 500 is suppressed.

  Further, at this time, the correction of the threshold value Ct according to the presence / absence of the structure is performed only on the stationary object. That is, the threshold Ct of the predicted collision time TTC for the moving object is maintained as Ct1. A structure that can cause an erroneous detection of an obstacle is a stationary object. By adding such a limitation, the safety system control process according to the present embodiment is inherently an operation target of the safety system 500. For example, the safety system 500 can be sufficiently effectively operated with respect to a moving body such as a forward vehicle. That is, according to the present embodiment, a very high profit is provided in practice that the safety system 500 can be operated as efficiently as possible, and the malfunction can be reliably prevented. .

  The present invention is not limited to the above-described embodiments, and can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. Is also included in the technical scope of the present invention.

1 is a block diagram conceptually showing a configuration of a portion related to a vehicle control device according to the present invention in a vehicle according to a first embodiment of the present invention. 3 is a flowchart of a safety system control process executed by an ECU in the vehicle of FIG. It is a flowchart of the obstacle detection process performed as one process of the safety system control process of FIG. FIG. 4 is a schematic diagram conceptually showing characteristics of a threshold value S of a reflected wave intensity Pr referred to in the obstacle detection process of FIG. 3. FIG. 6 is another schematic diagram conceptually showing the characteristic of the threshold value S. It is a flowchart of the safety system control process which concerns on 2nd Embodiment of this invention. It is a flowchart of the collision flag setting process performed as one process of the safety system control process of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Vehicle, 100 ... ECU, 200 ... Navigation device, 300 ... Forward millimeter wave radar, 400 ... Vehicle speed sensor, 500 ... Safety system, 510 ... Braking device, 520 ... Seat belt control device, 530 ... Alarm device.

Claims (6)

Detection means capable of detecting the object by emitting a detection wave having a predetermined wavelength to the front detection range and receiving a reflected wave formed by reflecting the emitted detection wave on the object, and safety during operation A vehicle control device for controlling a vehicle equipped with a safety system capable of improving
First determining means for determining whether or not the detected object is an obstacle according to a predetermined determination criterion;
An operation control means for operating the safety system in accordance with a predetermined operation standard with respect to the object determined to be the obstacle;
Second determining means for determining whether or not there is a structure that has been set in advance to cause an erroneous determination of the obstacle in advance;
And changing means for changing at least one of the determination standard and the operation standard so that the safety system becomes difficult to operate when the determination that the structure is present is made. A vehicle control device. The vehicle control device according to claim 1, wherein the structure includes a vertical structure that exists in a vertical direction of the vehicle and a step that exists on a travel route of the vehicle. The vehicle further includes position information acquisition means capable of acquiring a predetermined type of position information regarding the position of the vehicle and the position of the structure,
The vehicle control device according to claim 1, wherein the second determination unit determines whether or not the structure exists based on the acquired position information. The first determining means determines whether or not the detected object is an obstacle based on a comparison between an index value corresponding to the intensity of the received reflected wave and a first threshold,
The vehicle control device according to any one of claims 1 to 3, wherein the changing unit changes the threshold value as at least the determination criterion. Further comprising an acquisition means for acquiring a predicted collision time representing a time required for the object determined to be an obstacle and the vehicle to collide,
The operation control means operates the safety system based on a comparison between the acquired predicted collision time and a second threshold value,
The vehicle control device according to any one of claims 1 to 4, wherein the changing unit changes the second threshold value as at least the operation reference. Further comprising third determining means for determining whether the detected object is a stationary object;
6. The vehicle control device according to claim 1, wherein the changing unit changes the at least one corresponding to the object that has been determined to be the stationary object. 7. .

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